Gas-Microjet Reactive Scattering: Collisions of HCl and DCl with Cool Salty Water
Gas-Microjet Reactive Scattering: Collisions of HCl and DCl with Cool Salty Water
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DOI：
10.1021/acs.jpclett.5b02848
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发表时间：
2016-02-18
影响因子：
5.7
通讯作者：
Nathanson, Gilbert M.
中科院分区：
文献类型：
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作者：
Faust, Jennifer A.;Sobyra, Thomas B.;Nathanson, Gilbert M.
液体微喷流提供了一种强大的手段来研究真空中气体与咸水的反应，同时将气体与蒸汽的碰撞降至最低。我们用这项技术研究了在238K下，气态HCl和DCL分子撞击8摩尔的LiCl和LiBr溶液的命运。实验表明，如果HCl或DCL分子在任一种溶液的表面被热调节，那么它们很少蒸发。特别是，我们观察到在HCl碰撞后HCl的最小热解吸，并且没有明显的证据表明DCL碰撞后快速的界面DCL->；HCl交换。这些结果表明，表面的热运动通常不足以推动暂时捕获的HCl或DCL在电离和消失到溶液中之前回到气相中。相反，只有直接从表面散射的HCl和DCL分子才能逃脱进入。这些反冲分子在碰撞到LiBrH2O上时传递的能量比在LiClH2O上传递的能量小，反映了界面区域中Br2-的质量比Cl2-的质量大。
Liquid microjets provide a powerful means to investigate reactions of gases with salty water in vacuum while minimizing gas-vapor collisions. We use this technique to explore the fate of gaseous HCl and DCl molecules impinging on 8 molal LiCl and LiBr solutions at 238 K. The experiments reveal that HCl or DCl evaporate infrequently if they become thermally accommodated at the surface of either solution. In particular, we observe minimal thermal desorption of HCl following HCl collisions and no distinct evidence for rapid, interfacial DCl -> HCl exchange following DCl collisions. These results imply that surface thermal motions are not generally strong enough to propel momentarily trapped HCl or DCl back into the gas phase before they ionize and disappear into solution. Instead, only HCl and DCl molecules that scatter directly from the surface escape entry. These recoiling molecules transfer less energy upon collision to LiBr/H2O than to LiCl/H2O, reflecting the heavier mass of Br- than of Cl- in the interfacial region.